Doctor's Data Inc (DDI) are a "fully licensed and clinical laboratory" based in St Charles, Illinois[1].

Their main page describes their operation as "...provides specialty (sic) testing to healthcare practitioners around the world. A specialist and pioneer in essential and toxic elemental testing of multiple human tissues, the laboratory offers a wide array of functional testing. DDI’s tests are utilized in the assessment, detection, prevention, and treatment of heavy metal burden, nutritional deficiencies, gastrointestinal function, hepatic detoxification, metabolic abnormalities, and diseases of environmental origin."[2]

DDI recently sued the watchdog website Quackwatch as a result of the latter's linking them, and other organisations to the dubious practice of chelation therapy.[3]